ABSTRACT
BACKGROUND: Silibinin is the major active molecule of silymarin, the mixture of flavonolignans extracted from Cirsium japonicum. It has been used for the treatment of hepatitis and inflammation-related diseases. In the present study, the effects of silibinin on allergic inflammation and its signaling were investigated in the induced human mast cells. METHODS: Cell growth inhibition induced by silibinin was measured by MTS assay. Histamine release was measured by enzyme immunoassay. The tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) secreted protein levels and mRNA levels were measured by the ELISA assay and RT-PCR, respectively. The NF-κB promoter activity was examined by a luciferase assay. RESULTS: Silibinin suppressed the growth of HMC-1 cells and also reduced the production and mRNA expression of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-8. Moreover, silibinin inhibited the nuclear translocation of nuclear factor (NF)-κB through inhibition of the phosphorylation of IκBα and suppressed NF-κB transcriptional activity in stimulated HMC-1 cells. CONCLUSIONS: Taken together, these results indicate that silibinin inhibits the production of pro-inflammatory cytokines through inhibition of NF-κB signaling pathway in HMC-1 human mast cells, suggesting that silibinin could be used for the treatment of mast cell-derived allergic inflammatory diseases.
Subject(s)
Anti-Allergic Agents/pharmacology , Cytokines/antagonists & inhibitors , Mast Cells/drug effects , NF-kappa B/antagonists & inhibitors , Silymarin/pharmacology , Animals , Cell Line , Cell Survival/drug effects , Cytokines/genetics , Cytokines/metabolism , Humans , I-kappa B Kinase/metabolism , Mast Cells/metabolism , Mice , RNA, Messenger/metabolism , SilybinABSTRACT
Houttuynia cordata Thunb (HCT) is widely used in oriental medicine as a remedy for inflammation. However, at present there is no explanation for the mechanism by which HCT affects the production of inflammatory cytokines. The current study aimed to determine the effect of an essence extracted from HCT on mast cell-mediated inflammatory responses. Inflammatory cytokine production induced by phorbol myristate acetate (PMA) plus a calcium ionophore, A23187, was measured in the human mast cell line, HMC-1, incubated with various concentrations of HCT. TNF-α, IL-6 and IL-8 secreted protein levels were measured using an ELISA assay. TNF-α, IL-6 and IL-8 mRNA levels were measured using RT-PCR analysis. Nuclear and cytoplasmic proteins were examined by western blot analysis. The NF-κB promoter activity was examined by luciferase assay. It was observed that HCT inhibited PMA plus A23187-induced TNF-α and IL-6 secretion and reduced the mRNA levels of TNF-α, IL-6 and IL-8. It was also noted that HCT suppressed the induction of NF-κB activity, inhibited nuclear translocation of NF-κB and blocked the phosphorylation of IκBα in stimulated HMC-1 cells. It was concluded that HCT is an inhibitor of NF-κB and cytokines blocking mast cell-mediated inflammatory responses. These results indicate that HCT may be used for the treatment of mast cell-derived allergic inflammatory diseases.
Subject(s)
Cytokines/metabolism , Houttuynia/metabolism , NF-kappa B/metabolism , Plant Extracts/pharmacology , Signal Transduction/drug effects , Calcimycin/pharmacology , Cell Line , Cell Survival/drug effects , Cytokines/genetics , Houttuynia/chemistry , Humans , I-kappa B Proteins/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Interleukin-8/genetics , Interleukin-8/metabolism , Mast Cells/cytology , Mast Cells/drug effects , Mast Cells/metabolism , NF-KappaB Inhibitor alpha , NF-kappa B/antagonists & inhibitors , Phosphorylation , Plant Extracts/chemistry , Promoter Regions, Genetic , RNA, Messenger/metabolism , Tetradecanoylphorbol Acetate/pharmacology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolismABSTRACT
The effects of phenolic-rich fraction (PRF) from Rhus verniciflua Stokes (Anacardiaceae) on the activities of cellular signaling molecules that mediate inflammatory responses in LPS-induced RAW 264.7 macrophages were investigated. At various concentrations of PRF significantly inhibited NO, PGE(2) and TNF-alpha production in LPS-induced RAW 264.7 macrophage cells. The PRF also significantly inhibited iNOS and COX-2 protein expression in LPS-induced RAW 264.7 macrophage in a concentration-dependent manner. Transcription factor NF-kappaB plays a key role for the inducible expression of genes mediating proinflammatory effects and here, we show that PRF can inhibit the induction of NF-kappaB activity. The PRF effectively inhibited the iNOS and COX-2 protein expression through suppression of phospho-JNK1/2 activation. Study using PDA HPLC has found that the PRF contains several low molecular compounds (i.e. p-coumaric acid, fustin, kaempferol-3-O-glucoside, sulfuretin, butein, kaempferol). Our results indicate that the anti-inflammatory properties of PRF might result from the inhibition of pro-inflammatory mediators (e.g., NO, PGE(2) and TNF-alpha) by suppression of such signaling pathways as NF-kappaB and JNK1/2.
Subject(s)
Anti-Inflammatory Agents/pharmacology , JNK Mitogen-Activated Protein Kinases/drug effects , NF-kappa B/drug effects , Phenols/pharmacology , Rhus/chemistry , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/chemistry , Cell Line , Cell Survival , Cyclooxygenase 2/drug effects , Dinoprostone/metabolism , Dose-Response Relationship, Drug , Gene Expression Regulation/drug effects , JNK Mitogen-Activated Protein Kinases/metabolism , Lipopolysaccharides , Macrophages/drug effects , Macrophages/metabolism , Mice , NF-kappa B/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/drug effects , Phenols/administration & dosage , Phenols/isolation & purification , Phytotherapy , Plant Bark , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plants, Medicinal , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/drug effects , Tumor Necrosis Factor-alpha/metabolismABSTRACT
We investigated the effects of herb extracts, Rhus verniciflua, Agrimonia pilosa, Sophora japonica, and Paeonia suffruticosa, on the lowering of blood glucose levels and thiobarbituric acid reactive substances (TBARS) in streptozotocin (STZ)-induced diabetic rats. After 4 weeks, oral administration of Rhus verniciflua extract (50 mg/kg) exhibited a significant decrease in blood glucose levels in diabetic rats (P<0.05). Blood TBARS concentrations, the products of glucose oxidation in blood, were also lowered by Rhus verniciflua extract supplementation. In addition, Sophora japonica and Paeonia suffruticosa extracts significantly reduced TBARS levels versus diabetic controls. Serum concentrations of liver-function marker enzymes, GOT and GPT, were also restored by Rhus verniciflua (50 mg/kg) supplementation in diabetic rats.
